Wiring A 7-Way Harness For A 2010 Mercedes GLK350

Updated 10/09/2013 | Published 10/07/2013

Products Featured in This Question

Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires

(3400)

$103.72

ZCI Circuit Protected Vehicle Wiring Harness w/ 4-Pole Flat Trailer Connector and Installation Kit

(522)

$191.76

Curt No-Drill Bracket for 6-Way or 7-Way Round Trailer Connector Mounting Bracket - Long

(301)

$30.92

Question:

Hi - I have a 2010 Mercedes GLK 350 with the Curt Hitch, and need to figure out a way to hook up a standard 7-pin male trailer hookup from a Featherlite trailer. Everything Ive found online is for connecting a 4-pin setup. Is there anything that exists for this option for this vehicle? Thanks in advance for any help.

asked by: Matt S

Expert Reply:

We do offer an option for your 2010 Mercedes-Benz GLK350. You will have to install a 4-way harness and then a universal installation kit that uses the 4-way harness along with additional wiring to make a 4-way to 4-way and 7-way adapter. Always test the wires by function and not by color as auto manufacturers may use different color wires for different functions.

Since your GLK350 has a Pulse Width Modulation System ( PWM), The 4-way harness I recommend is part # 119250KIT. This has the required powered converter, and the needed hardware for installation. I have linked you to an FAQ article for wiring.

I would then recommend the Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat, part # ETBC7. This kit will plug into the 4-way, and then you will have to attach the remaining wires. The black wire from the 7-way will go to your 12 volt battery, the purple wire on the 7-way will attach to the reverse light wire, and the blue wire will attach to the brake controller. This kit includes the hardware needed for installation and does include a circuit tester. I have linked you to some FAQ articles for this kit.

I would also suggest a no-drill long bracket like part # C57202. This attaches to the hitch and provides a sturdy mount for the 7-way bracket and harness. I have linked you to a product review video for this bracket.

expert reply by: Jeffrey L